Air carrier large transport altitude deviation crossing restriction not met.

Attributes
ACN	92780
Time
Date	198808
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : psp
State Reference	CA
Altitude	msl bound lower : 15000 msl bound upper : 16000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla artcc : zla
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : direct enroute airway : v16
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 4000 flight time type : 1000
ASRS Report	92780
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : undershoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Clearance was to cross bands intersection (34 mi 78 degree right pdz/21 mi 258 degree right psp). Descending from FL240 to 15000' into ont, I had switched from my high altitude chart to a low altitude chart for the radials of V16. I noted bands intersection as 34/21 DME. I then got out my lax area chart as I was descending. Bands intersection is not on the lax chart, but I got busy reviewing the approach chart for ont as I wanted to be done before descending below 10000'. Center called and gave us a frequency change and asked our altitude. We were at 15500'. I looked at the DME and it was 24 mi past psp on the 258 degree right. In my mind I had bands intersection as 21 mi from pdz, 34 mi past psp. I had wanted to get down early so fortunately I was probably at 16000' over bands rather than higher if I had been flying a normal profile. The problem would not have occurred had I not been switching charts and reviewing the approach plate during descent. Also the last chart I had in front of me did not have bands intersection on it. I then confused the DME mileages to identify the intersection.

Original NASA ASRS Text

Title: ACR LGT ALT DEVIATION CROSSING RESTRICTION NOT MET.

Narrative: CLRNC WAS TO CROSS BANDS INTXN (34 MI 78 DEG R PDZ/21 MI 258 DEG R PSP). DSNDING FROM FL240 TO 15000' INTO ONT, I HAD SWITCHED FROM MY HIGH ALT CHART TO A LOW ALT CHART FOR THE RADIALS OF V16. I NOTED BANDS INTXN AS 34/21 DME. I THEN GOT OUT MY LAX AREA CHART AS I WAS DSNDING. BANDS INTXN IS NOT ON THE LAX CHART, BUT I GOT BUSY REVIEWING THE APCH CHART FOR ONT AS I WANTED TO BE DONE BEFORE DSNDING BELOW 10000'. CENTER CALLED AND GAVE US A FREQ CHANGE AND ASKED OUR ALT. WE WERE AT 15500'. I LOOKED AT THE DME AND IT WAS 24 MI PAST PSP ON THE 258 DEG R. IN MY MIND I HAD BANDS INTXN AS 21 MI FROM PDZ, 34 MI PAST PSP. I HAD WANTED TO GET DOWN EARLY SO FORTUNATELY I WAS PROBABLY AT 16000' OVER BANDS RATHER THAN HIGHER IF I HAD BEEN FLYING A NORMAL PROFILE. THE PROB WOULD NOT HAVE OCCURRED HAD I NOT BEEN SWITCHING CHARTS AND REVIEWING THE APCH PLATE DURING DSCNT. ALSO THE LAST CHART I HAD IN FRONT OF ME DID NOT HAVE BANDS INTXN ON IT. I THEN CONFUSED THE DME MILEAGES TO IDENT THE INTXN.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.